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From: steve@jplgodo.UUCP (Steve Schlaifer x3171 156/224)
Newsgroups: net.astro.expert
Subject: Re: black holes and comets
Message-ID: <587@jplgodo.UUCP>
Date: Tue, 4-Mar-86 12:53:04 EST
Article-I.D.: jplgodo.587
Posted: Tue Mar  4 12:53:04 1986
Date-Received: Fri, 7-Mar-86 06:44:56 EST
References: <1457@decwrl.DEC.COM>
Organization: Jet Propulsion Labs, Pasadena, CA
Lines: 23
Summary: comets are close by, black holes a long ways off

In article <1457@decwrl.DEC.COM>, goutal@dec-parrot.UUCP writes:
> I'm not an expert, I'm asking for an expert answer on behalf of my
> six-year-old daughter (who's no expert either).
> 
> The question she asks is, why don't the comets get gobbled up by
> black holes out beyond the planets?
> 
Essentially, comets are very close to the sun, stars and black holes, which
are just really big stars that have collapsed into themselves, are very
far away.  In the same way that the stars that we see at night don't
have any discernable affect on the motions of the planets or the comets,
black holes also have no affect on the planets or comets.  They are just too
far off for their gravity to have much effect.  Anything that
was both close enough and big enough to gobble comets, would also cause
very large disturbances in the orbits of the planets which would be easily
detected by modern (or even primitive) instruments.
-- 

...smeagol\			Steve Schlaifer
......wlbr->!jplgodo!steve	Advance Projects Group, Jet Propulsion Labs
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				Pasadena, California, 91109
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